<template>
  <div id="container">
    <!-- 上一页、下一页 -->

    <div class="right-btn">
      <!-- 输入页码 -->
      <div class="pageNum">
        <input v-model.number="currentPage" type="number" class="inputNumber" @input="inputEvent()"> / {{pageCount}}
      </div>
      <div @click="changePdfPage('first')" class="turn">
        首页
      </div>
      <!-- 在按钮不符合条件时禁用 -->
      <div @click="changePdfPage('pre')" class="turn-btn" :style="currentPage===1?'cursor: not-allowed;':''">
        上一页
      </div>
      <div @click="changePdfPage('next')" class="turn-btn" :style="currentPage===pageCount?'cursor: not-allowed;':''">
        下一页
      </div>
      <div @click="changePdfPage('last')" class="turn">
        尾页
      </div>
    </div>

    <div class="pdfArea">
      <pdf :src="src" ref="pdf" v-show="loadedRatio===1" :page="currentPage"
      @num-pages="pageCount=$event"
        @progress="loadedRatio = $event"
         @page-loaded="currentPage=$event" @loaded="loadPdfHandler"
        @link-clicked="currentPage = $event" style="display: inline-block;width:100%"
        id="pdfID"></pdf>
    </div>
    <!-- 加载未完成时，展示进度条组件并计算进度 -->
    <div class="progress" v-show="loadedRatio!==1">
      <el-progress type="circle" :width="70" color="#53a7ff" :percentage="Math.floor(loadedRatio * 100)"></el-progress>
      <br>
      <!-- 加载提示语 -->
      <span>{{remindShow}}</span>
    </div>
  </div>
</template>

<script>
  import pdf from 'vue-pdf'
  export default {
    name:"Pdf",
    components: {
      pdf
    },
    computed: {},
    data() {
      return {
        src: '',
        // ----- loading -----
        remindText: {
          loading: '加载文件中，文件较大请耐心等待...',
          refresh: '若卡住不动，可刷新页面重新加载...'
        },
        remindShow: '加载文件中，文件较大请耐心等待...',
        intervalID: '',
        // ----- vuepdf -----
        // src静态路径: /static/xxx.pdf
        // src服务器路径: 'http://.../xxx.pdf'
        // 当前页数
        currentPage: 0,
        // 总页数
        pageCount: 0,
        // 加载进度
        loadedRatio: 0,
        baseUrl: process.env.VUE_APP_BASE_API,
      }
    },
    created() {
      const src = this.$route.params && this.$route.params.src;
      const zltm = this.$route.params && this.$route.params.zltm;
      this.$nextTick(() => {
        let visitedViews = this.$store.state.tagsView.visitedViews;
        visitedViews.some(v => {
          if (v.path == this.$route.path) {
            v.title =  zltm;
          }
        })

      });

      if ((src.indexOf(this.baseUrl) === -1) & src.indexOf('http') === -1) {
        this.src = this.baseUrl +'printtemp/'+ src;
      } else {
        this.src = src;
      }

    },
    destroyed() {
      // 在页面销毁时记得清空 setInterval
      clearInterval(this.intervalID)
    },
    mounted() {
      // 更改 loading 文字
      this.intervalID = setInterval(() => {
        this.remindShow === this.remindText.refresh ?
          this.remindShow = this.remindText.loading :
          this.remindShow = this.remindText.refresh
      }, 4000)
      // 监听滚动条事件
      // this.listenerFunction()
    },
    methods: {
      // 监听滚动条事件
      listenerFunction(e) {
        document.getElementById('container').addEventListener('scroll', true)
      },
      // 页面回到顶部
      toTop() {
        document.getElementById('container').scrollTop = 0
      },
      // 输入页码时校验
      inputEvent() {
        if (this.currentPage > this.pageCount) {
          // 1. 大于max
          this.currentPage = this.pageCount
        } else if (this.currentPage < 1) {
          // 2. 小于min
          this.currentPage = 1
        }
      },
      // 切换页数
      changePdfPage(val) {
        if (val === 'pre' && this.currentPage > 1) {
          // 切换后页面回到顶部
          this.currentPage--
          this.toTop()
        } else if (val === 'next' && this.currentPage < this.pageCount) {
          this.currentPage++
          this.toTop()
        } else if (val === 'first') {
          this.currentPage = 1
          this.toTop()
        } else if (val === 'last' && this.currentPage < this.pageCount) {
          this.currentPage = this.pageCount
          this.toTop()
        }
      },

      // pdf加载时
      loadPdfHandler(e) {
        // 加载的时候先加载第一页
        this.currentPage = 1
      },

      // 禁用鼠标右击、F12 来禁止打印和打开调试工具
      prohibit() {
        // console.log(document)
        document.oncontextmenu = function() {
          return false
        }
        document.onkeydown = function(e) {
          if (e.ctrlKey && (e.keyCode === 65 || e.keyCode === 67 || e.keyCode === 73 || e.keyCode === 74 || e
              .keyCode === 80 || e.keyCode === 83 || e.keyCode === 85 || e.keyCode === 86 || e.keyCode === 117)) {
            return false
          }
          if (e.keyCode === 18 || e.keyCode === 123) {
            return false
          }
        }
      }
    }
  }
</script>

<style scoped>
  #container {
    overflow: auto;
    height: 800px;
    font-family: PingFang SC;
    width: 100%;
    display: flex;
    /* justify-content: center; */
    position: relative;
  }

  /* 右侧功能按钮区 */
  .right-btn {
    position: fixed;
    right: 5%;
    bottom: 15%;
    width: 120px;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    z-index: 99;
  }

  .pdfArea {
    width: 80%;
  }

  /* ------------------- 输入页码 ------------------- */
  .pageNum {
    margin: 10px 0;
    font-size: 18px;
  }

  /*在谷歌下移除input[number]的上下箭头*/
  input::-webkit-outer-spin-button,
  input::-webkit-inner-spin-button {
    -webkit-appearance: none !important;
    margin: 0;
  }

  /*在firefox下移除input[number]的上下箭头*/
  input[type='number'] {
    -moz-appearance: textfield;
  }

  .inputNumber {
    border-radius: 8px;
    border: 1px solid #999999;
    height: 35px;
    font-size: 18px;
    width: 60px;
    text-align: center;
  }

  .inputNumber:focus {
    border: 1px solid #00aeff;
    background-color: rgba(18, 163, 230, 0.096);
    outline: none;
    transition: 0.2s;
  }

  /* ------------------- 切换页码 ------------------- */
  .turn {
    background-color: #888888;
    opacity: 0.7;
    color: #ffffff;
    height: 70px;
    width: 70px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 5px 0;
  }

  .turn-btn {
    background-color: #000000;
    opacity: 0.6;
    color: #ffffff;
    height: 70px;
    width: 70px;
    border-radius: 50%;
    margin: 5px 0;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .turn-btn:hover,
  .turn:hover {
    transition: 0.3s;
    opacity: 0.5;
    cursor: pointer;
  }

  /* ------------------- 进度条 ------------------- */
  .progress {
    position: absolute;
    right: 50%;
    top: 50%;
    text-align: center;
  }

  .progress>span {
    color: #199edb;
    font-size: 14px;
  }
</style>
